Dynamo-electric machine.



so great that the short circuiting e'ect of the iiuid outside of thefield is practically negligible. Conducting plates D are placed at thecenter of the pipe section to serve as terminals for the machine, fromwhich current may be led, or to which current may be supplied when themachine is acting as a generator or motor. A

In order to afford a ma etic circuit of fairly high efficiency, theimension of the ntral cross section of the pipe in the direction of theflux is made much smaller than the dimension at right angles thereto, asis best shown in Fig. 2.

I do not desire to limit myself to the par ticular construction andarrangement of parts here shown but aim in the appended claims to covera modications w ich are within the scope of my invention.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is,-

1. A dynamo-electric machine comprising an insulated pipe, a eld magnethaving poles extending on opposite sides of said pipe so as to produce aiiux passing transversely through said pipe, the central portions of theopposite pole faces being substantially parallel with each other and theends of the poles being beveled so that the pole faces make an acute anle with each other and consequently gra ually recede from each other,and current terminals within the pipe where the pole faces are parallel.

2. A dynamo electric machine comprising an insulated pipe ofcomparatively small' cross section near its center and daring at theends, a field magnet and Winding adapted to produce a flux assingtransversely through said pipe, an current` terminals within the centralportion of said pipel on i an insulated pipe opposite sides of the pathof said flux.

3. A dynamo electric machine comprisin of comparatively sma crosssection near its center and flaring at its ends, a eld magnet andwinding adapted to produce transversely through said pipe a nxcomparatively strong at the central orton -of the pipe, and graduallydiminis ling in strength toward its ends, and current terminals Withinthe central ortion of said pipe on opposite sides of t e path of said 4.A dynamo electric machine, comprising an insulated pipe of comparativelysmall cross section near its center and flaring at the ends, a fieldmagnet and winding adapted to produce a iiux passing transverselythrough said pipe, and current terminals Within the central portion ofsaid pipe on opposite sides of the path of said tlux, the dimension ofthe central cross section of the pipe in the direction of the flux beingmuch smaller than the dimension at right angles thereto.

5. A dynamo-electric machine comprising an insulated pipe, a fieldmagnet having poles extending on opposite sides of said pipe so as toproduce a tlux passing transversely through said pipe, the centralportions of the opposite pole faces being sub.

stantially para llel to each other and the ends of the pole beingbeveledso that the pole faces make an acute angle with each other andconsequently gradually recede from each other, the portion of the ipelying between the substantially parallel portions of the ole faces beingof uniform cross section with the di'fension in the direction of theflux much smaller than-the dimension at right angles hereto, and currentterminals within the centralportion of said pipe on opposite sides ofthe path of said flux.

In' witness whereof I have hereunto set my hand this 10th day of April1908.

JAKDB E. NOEGGERATH.

Witnees:

'BENJAMIN B. Hum., v

HELEN

